JP2021152355A - Geothermal power generation system - Google Patents

Abstract

To recover an output of a geothermal power generation system in which hot water is depleted, without receiving energy supply from the exterior.SOLUTION: Hot water pumped out from the underground is compressed by a booster pump, and is heated by a second-class absorption heat pump to increase the temperature, and steam with increased temeperature and pressure is supplied to a steam turbine. Since the temeperature and pressure of the steam in the steam turbine are increased, and the heat efficiency of the steam turbine is thus improved, a power generation amount of a generator in connection with the steam turbine can be recovered with less amount of hot water.SELECTED DRAWING: Figure 3

Description

The present invention relates to a geothermal power generation system that converts the thermal energy of hot water and steam in the ground into electrical energy.

Conventional flash geothermal power generation systems used in many geothermal power plants use a large amount of hot water as an energy source, so the hot water flow rate decreases and the hot water temperature drops as time passes from the start of operation. It falls into a state of depletion of hot water, which causes a problem that the amount of power generation decreases. In order to solve the problem that the amount of power generation is reduced due to the depletion of hot water, in the conventional flash type geothermal power generation system, the used hot water and the steam condensed water after driving the steam turbine are returned to the ground. However, although it has the effect of slowing the rate of hot water depletion, it is not a permanent measure. As a solution to this problem, the prior art document: Japanese Patent Application Laid-Open No. 2014-134106 discloses a geothermal system to which a second-class absorption heat pump is added. The solution is to use a Type 2 absorption heat pump to recover the heat of the used hot water that is returned to the ground to create a heating source, which is then used to generate steam and steam. By increasing the temperature and pressure of the steam supplied to the turbine to improve the thermal efficiency of the steam turbine, it is possible to generate electricity with a small amount of hot water pumped up, and the amount of power generation is restored. It has the feature that it is possible to recover the amount of power generation without receiving energy supply from the outside.

Japanese Unexamined Patent Publication No. 2014-134106

The problem to be solved by the present invention is to improve the thermal efficiency of the steam turbine by a simple method for the geothermal power generation system having the second-class absorption type heat pump of the prior art, and to increase the amount of power generation with a smaller amount of pumped hot water. It is to provide a recovery system.

A conduit through which hot water pumped from the ground flows, a pressurizing pump installed at a location in the ground of this conduit, a steam separator to which the hot water is supplied by this pressurizing pump, and a steam separator generated from this steam separator. A steam turbine to which steam is supplied, a generator interlocking with this steam turbine, a condenser in which steam emitted from the steam turbine condenses, an evaporator and an absorber and a regenerator, a condenser, a heat exchanger and a cooling tower. It is characterized by having a second-class absorption type heat pump, a conduit through which hot water circulates between the steam separator and the absorber, and a conduit through which hot water flows from the steam separator to the evaporator. And.

A steam separator to which hot water pumped from the ground is supplied, a steam separator to which hot water in the steam separator is supplied, a conduit connecting the steam separator and the steam separator, A pressurizing pump installed in the middle of this conduit, a steam turbine to which steam generated from the steam separator, a generator interlocking with the steam turbine, and a water condensing device in which steam emitted from the steam turbine is condensed. A second-class absorption heat pump having an evaporator, an absorber, a regenerator, a condenser, a heat exchanger, and a cooling tower, a conduit through which hot water circulates between the steam separator and the absorber, and the steam. It is characterized by including a conduit through which hot water flows from the separator to the evaporator.

A steam separator to which hot water pumped from the ground is supplied, a steam separator to which hot water in the steam separator is supplied, a conduit connecting the steam separator and the steam separator, A pressurizing pump installed in the middle of this conduit, a steam turbine to which steam generated from the steam separator, a generator interlocking with the steam turbine, and a water condensing device in which steam emitted from the steam turbine is condensed. A second-class absorption heat pump having an evaporator, an absorber, a regenerator, a condenser, a heat exchanger, and a cooling tower, a conduit through which hot water circulates between the steam separator and the absorber, and the steam. It is characterized by including a conduit through which hot water flows from the separator to the evaporator.

The challenge of providing a system that recovers power generation with a smaller amount of hot water pumped is to pressurize the hot water pumped from the ground with a pressure pump and heat the pressurized hot water with a second-class absorption heat pump. It will be solved by.

When hot water pumped from the ground is pressurized with a pressurizing pump and the pressurized hot water is heated, the temperature and pressure of the generated steam rises, so the temperature and pressure of the steam supplied to the steam turbine rises. However, the thermal efficiency of the turbine is improved and the amount of power generated can be increased.

This is because the geothermal power generation system having the type 2 absorption type heat pump of the present invention has the effect of improving the thermal efficiency and increasing the amount of power generation as compared with the geothermal power generation system having the type 2 absorption type heat pump of the prior art document. , The effect of recovering the amount of power generation can be obtained with a smaller amount of pumped hot water. Since the amount of hot water required for operation is reduced, the capacity of equipment such as condensers and cooling towers that make up the main body of the power generator is reduced, which has the effect of reducing equipment costs and when returning hot water to the ground. The effect of reducing the power used for the power generation can be obtained. In addition, the blockage life of the pipe due to the sediment in hot water is extended, and the effect of reducing the cost of equipment maintenance can be obtained. In addition, the time interval between the regular movement of production wells and reduction wells and additional excavation is extended, and the effect of suppressing equipment management costs can be obtained. In addition, since the lower limit temperature of hot water that can be used for geothermal power generation as a business is lowered, the effect of expanding the location of geothermal power generation can be obtained.

It is a schematic diagram explaining the geothermal power generation system which eliminates the output drop due to the depletion of hot water which installed the underground type pressure pump. (Example 1 of the present invention) It is a schematic diagram explaining the geothermal power generation system which solves the output drop due to the depletion of hot water by installing the pressure pump of the ground-mounted type. (Example 2 of the present invention) It is a schematic diagram explaining the geothermal power generation system which eliminates the output drop due to the depletion of hot water by installing another ground-mounted type pressurizing pump. (Example 3 of the present invention) It is a schematic diagram explaining the geothermal power generation system which does not release the gas such as hydrogen sulfide in hot water to the atmosphere. (Example 4 of the present invention) It is a schematic diagram explaining the geothermal power generation system which does not release a gas such as hydrogen sulfide in hot water having a reheater to the atmosphere. (Example 5 of the present invention) It is the schematic explaining the geothermal power generation system which suppresses the erosion which installed the superheater and the reheater. (Example 6 of the present invention) It is a schematic diagram explaining the geothermal power generation system which suppresses the erosion which installed the reheater. (Example 7 of the present invention) It is a model steam diagram which shows the enthalpy-entropy of steam in the geothermal power generation system which suppresses the erosion of Examples 6 and 7 of this invention. It is a schematic diagram explaining the geothermal power generation system of the closed Rankine cycle which has the type 2 absorption type heat pump which makes an emergency stop safely. (Example 8 of the present invention) It is a schematic diagram explaining the geothermal power generation system of the open Rankine cycle which has the type 2 absorption type heat pump which makes an emergency stop safely. (Example 9 of the present invention) The model figure of the pressure change in the air-water separator before and after the implementation of the present invention in the geothermal power generation system having the second type absorption heat pump.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a geothermal power generation system in which an underground installation type pressurizing pump 19 for explaining Example 1 of the present invention is installed to eliminate a decrease in output due to hot water depletion.

A geothermal power generation system generally consists of a geothermal power generation device main body and a second-class absorption heat pump.

The main body of the geothermal power generation device is composed of an air-water separator 11, a steam turbine 13, a generator 15, a condenser 16, a cooling tower 17, a pressurizing pump 19, and the like. , The regenerator 33, the condenser 34, the heat exchanger 35, the cooling tower 36, and the like.

The combination of heat medium and absorption liquid used in the Type 2 absorption heat pump mainly uses water as the heat medium and lithium bromide as the absorption liquid, considering that it operates in the temperature range from room temperature to about 200 ° C. A combination of an aqueous solution (hereinafter referred to as a lithium bromide aqueous solution) in which a rust preventive agent is added to the components is used. In addition to the combination of water and lithium bromide aqueous solution, there are combinations of water and sulfuric acid aqueous solution, ammonia and water, etc., but in the present invention, the combination of water and lithium bromide aqueous solution will be described.

The hot water W11 pumped from the ground is pressurized by the pressurizing pump 19, then flows through the conduit 22 and is supplied to the steam separator 11. Hot water W14 circulates in the conduit 24 between the air-water separator 11 and the absorber 32 of the absorption type heat pump, and the hot water W14 is heated in the absorber 32 to boil and returned to the air-water separator 11. It is separated into hot water and steam.

The steam S11 separated from the hot water in the steam separator 11 is supplied to the steam turbine 13 to drive the steam turbine 13, and itself becomes low-temperature low-pressure steam S14 and is supplied to the condenser 16 for cooling. It is cooled by water C11, condensed, and mixed with cooling water C11. The cooling water C11 increases due to the condensation and mixing of the steam S14, and the increased amount is returned to the ground from the reduction well X12.

The hot water W13 discharged from the air-water separator 11 flows through the conduit 23 connecting the air-water separator 11 and the evaporator 31 of the second-class absorption type heat pump and is introduced into the evaporator 31, and the evaporator 31 is regenerated. After the heat is taken away by the vessel 33, it is returned to the ground from the reduction well X11.

In the evaporator 31 of the second-class absorption heat pump, the water in the vessel is boiled by heating the hot water W13, and the generated steam is absorbed by the lithium bromide aqueous solution in the absorber 32 at the same pressure. In the absorber 32, the hot water W14 from the steam separator 11 is heated by the absorbed heat generated when the steam is absorbed and boils. The lithium bromide aqueous solution in the absorber 32 that has absorbed the steam from the evaporator 31 is supplied into the regenerator 33 via the heat exchanger 35, and is boiled in the regenerator 33 by heating the hot water W13 to be boiled in the absorber 33. The vapor absorbed in 32 is released. Then, the lithium bromide aqueous solution that released the vapor is returned to the absorber 32 via the heat exchanger 35. The steam generated by boiling the lithium bromide aqueous solution in the regenerator 33 is cooled by the cooling water C12 in the condenser 34 at the same pressure and returned to water, and this water is returned to the evaporator 31.

Between the evaporator 31 and the absorber 32, the heat taken from the hot water W13 in the evaporator 31 is used for heating and boiling the hot water W14 in the absorber 32. Between the regenerator 33 and the condenser 34, the heat used for the regeneration of the lithium bromide aqueous solution (recovery of the lithium bromide concentration of the lithium bromide aqueous solution and the production of water to the evaporator 31) in the regenerator 33 is condensed. Heat is transferred to the cooling water C12 in the vessel 34, transferred to the cooling tower 36 by the cooling water C12, and discharged from the cooling tower 36 into the atmosphere.

Table 1 below shows a conventional single-flash geothermal power generation system, a geothermal power generation system having an absorption heat pump described in the prior art document (Japanese Patent Laid-Open No. 2014-134106), and a geothermal power generation system for eliminating a decrease in output due to hot water depletion, and the present invention. An example of comparison of a geothermal power generation system for eliminating a decrease in output due to hot water depletion having a pressurizing pump and an absorption type heat pump of Example 1 is shown. This comparative example is created from the simulation calculation results when various energy losses are ignored under the same conditions where hot water pumped from the ground at a temperature of 150 ° C. and a pressure of 0.48 MPa is used at 100 kg / s.

In the geothermal power generation system for eliminating the output decrease due to the depletion of hot water according to the first embodiment of the present invention, the hot water W11 is pressurized to a pressure of 1.55 MPa by the pressurizing pump 19 and supplied to the steam separator 11. This hot water is heated by a type 2 absorption type heat pump to generate steam at a temperature of 200 ° C. and a pressure of 1.55 MPa, and this steam drives the steam turbine 13. When the steam turbine outlet pressure is 0.1 MPa at atmospheric pressure, the theoretical power generation amount is 2,430 kJ / s, and the thermal efficiency is 3.9%.

Looking at the entire system that combines the main body of the power generator and the second-class absorption type heat pump, the retained heat of the hot water W11 pumped from the ground with a temperature difference of 60 ° C from 150 ° C to 90 ° C is recovered, and the temperature is 200 ° C. High-temperature and high-pressure steam with a pressure of 1.55 MPa is generated to drive the steam turbine 13 to generate electricity.

On the other hand, in the conventional flash type geothermal power generation system, hot water having a temperature of 150 ° C. and a pressure of 0.48 MPa is depressurized to 0.27 MPa (saturation temperature 125 ° C.) to generate steam, and the temperature difference of hot water is 25 (=). The retained heat at 150-125) ° C is recovered, and steam at a temperature of 125 ° C and a pressure of 0.27 MPa is supplied to the steam turbine to generate power.

Compared with the flash type geothermal power generation system of the prior art, the geothermal power generation system having the absorption type heat pump of the first embodiment of the present invention has a large flow rate of steam supplied to the steam turbine and high temperature and pressure, so that the thermal efficiency is high. Is 3.3 (≈3.9 / 1.2) times higher, which has the effect of making it possible to reduce the amount of hot water pumped from the ground to 1 / 3.3.

Further, in the geothermal power generation system having the absorption type heat pump described in the prior art document, the retained heat having a temperature difference of 60 ° C. from the temperature of hot water of 150 ° C. to 90 ° C. is recovered by using the type 2 absorption type heat pump. Steam with a temperature of 150 ° C. and a pressure of 0.48 MPa is generated, and this steam is supplied to a steam turbine to generate power.

Compared with the geothermal power generation system having an absorption type heat pump described in this prior art document, the geothermal power generation system having an absorption type heat pump according to the first embodiment of the present invention has a higher temperature and pressure of steam supplied to the steam turbine. Therefore, the thermal efficiency is increased by about 1.7 (≈3.9 / 2.3) times, and there is an effect that the amount of hot water pumped from the ground can be reduced to about 60%.

However, in the geothermal power generation system in which the underground installation type pressure pump described in FIG. 1, which is the first embodiment of the present invention, is installed to eliminate the output decrease due to the depletion of hot water, the pressure pump is installed underground. Therefore, there is a problem that the maintenance cost becomes large.

The problem of increased maintenance costs can be solved by changing the pressure pump installed underground to ground installation, but on the other hand, the hot water is depressurized by the time it reaches the ground, causing self-evaporation and mixing with air and water. This causes a problem that it becomes difficult to pressurize with a general pressurizing pump.

The problem that it becomes difficult to pressurize hot water due to the mixed state of steam is solved by installing a steam separator and pressurizing with the pressurizing pump only for the separated hot water. The separated steam is supplied during the expansion of the steam turbine to eliminate thermal energy loss.

The geothermal power generation system in which the ground-mounted type pressurizing pump 49 for explaining the second embodiment of the present invention shown in FIG. 2 is installed to eliminate the output decrease due to the depletion of hot water is generally a geothermal power generation device main body and a second type absorption type. It consists of a heat pump. The main body of the geothermal power generation device is composed of a gas-water separator 41 and 42, a steam turbine 43, a generator 45, a condenser 46, a cooling tower 47, a pressurizing pump 49, etc. It is composed of a vessel 62, a condenser 63, a condenser 64, a heat exchanger 65, a cooling tower 66, and the like.

Compared with the geothermal power generation system of Example 1 above, the underground type pressurizing pump was changed to the ground type pressurizing pump 49, and the number of air-water separators increased to 41 and 42. The hot water W42 separated by the gas-water separator 41 is supplied to the gas-water separator 42 by the pressurizing pump 49.

Further, due to these changes, the hot water W44 circulates between the absorber 62 and the high-pressure steam separator 42, and the hot water W43 guided to the evaporator 61 and the regenerator 63 is a high-pressure steam separator. It has been changed that the steam S42 generated from the high-pressure steam separator 42 and the steam S41 from the low-pressure steam separator 41 are supplied to the steam turbine 43 to be taken out from the 42.

The hot water W41 pumped up from the ground flows in the conduit 52 and self-evaporates when the pressure decreases as it approaches the ground surface, and is supplied to the steam separator 41 in a mixed state of steam and hot water. And separated into steam. The separated hot water W42 is pressurized by the pressurizing pump 49 and supplied to the high-pressure steam separator 42.

Hot water W44 circulates in the conduit 54 between the high-pressure steam separator 42 and the absorber 62 of the absorption heat pump, and the hot water W44 is heated and boiled in the absorber 62 to the steam separator 42. It is returned and separated into hot water and steam.

The separated steam S42 is supplied to the steam turbine 43 to drive the steam turbine 43, and itself becomes low-temperature low-pressure steam S44 and is supplied to the condenser 46. It is mixed with water C41. The cooling water C41 increases due to the condensation and mixing of the steam S44, and the increased amount is returned to the ground from the reduction well X42.

The hot water W43 discharged from the high-pressure air-water separator 42 flows through the conduit 53 connecting the air-water separator 42 and the evaporator 61 of the second-class absorption heat pump, is introduced into the evaporator 61, and is introduced into the evaporator. After the heat is taken away by the 61 and the regenerator 63, it is returned to the ground from the reduction well X41.

In the evaporator 61, the water in the vessel is boiled into steam by heating the hot water W43, and this steam is absorbed by the lithium bromide aqueous solution in the absorber 62 at the same pressure. In the absorber 62, the hot water W44 from the steam separator 42 is heated and boiled by the absorbed heat generated when the steam is absorbed. The lithium bromide aqueous solution in the absorber 62 that has absorbed the steam from the evaporator 61 is supplied into the regenerator 63 via the heat exchanger 65, and boils in the regenerator 63 by heating the hot water that has passed through the evaporator 61. Then, the vapor absorbed in the absorber 62 is released. Then, the lithium bromide aqueous solution that has released the vapor is returned to the absorber 62 via the heat exchanger 65. The steam generated by boiling the lithium bromide aqueous solution in the regenerator 63 is cooled by the cooling water C42 in the condenser 64 at the same pressure and returned to water, and this water is returned to the evaporator 61.

Between the evaporator 61 and the absorber 62, the heat taken from the hot water W43 in the evaporator 61 is used for heating and boiling the hot water W44 in the absorber 62. Between the regenerator 63 and the condenser 64, the heat retained by the steam generated by the regeneration of the lithium bromide aqueous solution in the regenerator 63 is transferred to the condenser 64 by the movement of the steam, and is transferred to the cooling water C42 in the condenser 64. It is transmitted, transferred to the cooling tower 46 by the cooling water C42, and discharged from the cooling tower 46 into the atmosphere.

The performance of the geothermal power generation system according to the second embodiment of the present invention can be ignored because the steam flow rate W41 supplied from the steam separator 41 to the steam turbine 43 is small, so that the performance of the geothermal power generation system according to the first embodiment of the present invention can be ignored. Can be approximated to.

In the geothermal power generation system of the second embodiment of the present invention, as compared with the geothermal power generation system of the present invention of the first embodiment, the pressurizing pump 49 for pressurizing hot water is installed on the ground, so that the cost of the system is reduced. The effect and the effect of facilitating operation management can be obtained.

However, in the geothermal power generation systems of Examples 1 and 2 of the present invention, the pressurizing pump and the type 2 absorption heat pump have a large capacity, and the influence on the equipment cost and the operation and maintenance cost cannot be ignored. And the problem of reducing the capacity of the second-class absorption heat pump remains.

The challenge of reducing the capacity of the pressurizing pump and the type 2 absorption heat pump is to limit the amount of hot water pressurized by the pressurizing pump to the amount of steam supplied to the steam turbine, and the amount of heat exchanged for the type 2 absorption heat pump. Is solved by limiting the amount of heat of vaporization of hot water supplied to the steam pump.

Limiting the amount of hot water to be pressurized by the pressurizing pump to the amount of steam supplied to the steam turbine and limiting the amount of exchange heat of the type 2 absorption heat pump to the amount of heat of vaporization of hot water supplied to the steam turbine is second. This can be achieved by changing the hot water outlet to be introduced into the evaporator of the seed absorption type heat pump from the high-pressure steam separator 42 to the low-pressure steam separator 41.

FIG. 3 shows a geothermal power generation system in which a ground-mounted pressurizing pump 79 for explaining Example 3 of the present invention is installed to eliminate a decrease in output due to hot water depletion. It consists of a geothermal power generation device main body and a second-class absorption heat pump. The main body of the geothermal power generation device is composed of a gas-water separator 71 and 72, a steam turbine 73, a generator 75, a condenser 76, a cooling tower 77, a pressure pump 79, etc. It is composed of a vessel 92, a condenser 93, a condenser 94, a heat exchanger 95, a cooling tower 96, and the like.

The hot water W71 pumped up from the ground flows in the conduit 81 and self-evaporates when the pressure decreases as it approaches the ground surface, and is supplied to the steam separator 71 in a mixed state of steam and hot water. Separated into hot water. Of the separated hot water, only the hot water W72 supplied as steam to the steam turbine is pressurized by the pressurizing pump 79 and supplied to the high-pressure steam separator 72. The remaining hot water W73 is introduced into the evaporator 91 of the second-class absorption heat pump. The separated steam S71 is supplied during the expansion of the steam turbine 73.

Hot water W74 circulates in the conduit 84 between the high-pressure steam separator 72 and the absorber 92 of the absorption heat pump, and the hot water W74 is heated and boiled in the absorber 92 to the steam separator 72. It is returned and separated into hot water and steam.

The separated steam S72 is supplied to the steam turbine 73 to drive the steam turbine 73, and itself becomes low-temperature low-pressure steam S74 and is supplied to the condenser 76. It is mixed with water C71. The cooling water C71 increases due to the condensation and mixing of the steam S74, and the increased amount is returned to the ground from the reduction well X72.

The hot water W73 discharged from the low-pressure air-water separator 71 flows through the conduit 83 connecting the air-water separator 71 and the evaporator 71 of the second-class absorption type heat pump, is introduced into the evaporator 91, and is introduced into the evaporator 91. After being deprived of heat by the regenerator 93, it is returned to the ground from the reduction well X71.

In the evaporator 91, the water in the vessel is boiled into steam by heating the hot water W73, and this steam is absorbed by the lithium bromide aqueous solution in the absorber 92 at the same pressure. In the absorber 92, the hot water W74 from the steam separator 72 is heated and boiled by the absorbed heat generated when the steam is absorbed. The lithium bromide aqueous solution in the absorber 92 that has absorbed the steam from the evaporator 91 is supplied into the regenerator 93 via the heat exchanger 95, and boils in the regenerator 93 by heating the hot water that has passed through the evaporator 91. Then, the vapor absorbed in the absorber 92 is released. Then, the lithium bromide aqueous solution that has released the vapor is returned to the absorber 92 via the heat exchanger 95. The steam generated by boiling the lithium bromide aqueous solution in the regenerator 93 is cooled by the cooling water C72 in the condenser 94 at the same pressure and returned to water, and this water is returned to the evaporator 91.

Between the evaporator 91 and the absorber 92, the heat taken from the hot water W73 in the evaporator 91 is used for heating and boiling the hot water W74 in the absorber 92. Between the regenerator 93 and the condenser 94, the retained heat of the steam generated by the regeneration of the lithium bromide aqueous solution in the regenerator 93 is transferred to the condenser 94 by the movement of the steam and transferred to the cooling water C72 in the condenser 94. Then, it is transferred to the cooling tower 76 by the cooling water C72, and is discharged from the cooling tower 76 into the atmosphere.

The capacity of the pressurizing pump 79 in Example 3 of the present invention corresponds to the steam flow rate of 5.2 kg / s shown in the calculation example of Table 1, and is 1/19.2 of the amount of hot water pumped from the ground of 100 kg / s. Decreases to.

The pressure pump 79 capacity of the third embodiment of the present invention / the pressure pump 49 capacity of the second embodiment of the present invention is the steam flow rate supplied to the steam turbine / the amount of hot water pumped from the ground, and 5.2 / 100 = 1. /19.2 = 0.052.

At this time, the capacity of the second-class absorption heat pump of Example 3 of the present invention is 11,260 kJ / s, which is the amount of heat for steaming 5.2 kg / s of hot water supplied to the steam turbine. Type 2 absorption heat pump capacity = 1 / 2.9 of 32,210 kJ / s, which is the sum of the amount of heat for converting hot water pumped from the ground to saturated water and the amount of heat for generating steam of 5.2 kg / s. Decreases to.

The second-class absorption heat pump capacity of Example 3 of the present invention is the amount of heat that vaporizes the hot water supplied to the steam turbine, and is (turbine steam flow rate) x (steam enthalpy at the turbine inlet-hot water enthalpy pumped up). , = 5.2x (2793.2-628.5) ≈11,260 kJ / s.

The capacity of the second-class absorption type heat pump according to the second embodiment of the present invention is (heating amount of the total amount of hot water) + (heat generated by steam supplied to the steam turbine), and ((total amount) x (saturated hot water entertainment pumping). Hot water enthalpy)) + ((turbine steam flow rate) x (turbine inlet steam enthalpy-saturated hot water enthalpy)), (100x (838-628.5)) + 5.2x (2793.2-838) It is about (20,960 + 11,260), which is 32,210 kJ / s. The capacity of the second-class absorption heat pump of Example 3 of the present invention / the capacity of the second-class absorption heat pump of Example 2 of the present invention is 11,260 / 32,210 = 1 / 2.9 = 0.35.

The geothermal power generation system of the present invention of Example 3 is pressurized to pressurize hot water without deteriorating performance such as thermal efficiency and power generation amount as compared with the geothermal power generation system of the present invention of Example 2 or 1. Since the capacities of the pump 79 and the second-class absorption type heat pump can be reduced, an economical effect of reducing the equipment cost and the operating cost can be obtained.

Table 1 shows a single-flash geothermal power generation system of the prior art, a geothermal power generation system in which a second-class absorption type heat pump of the prior art document is installed to reduce the amount of hot water, and a pressurizing pump and a second-class absorption of the first embodiment of the present invention. A comparison of geothermal power generation systems in which a type heat pump is installed and the amount of hot water is reduced is shown.

Example 4 relates to a geothermal power generation system that does not release gas such as hydrogen sulfide to the atmosphere. A conventional flash geothermal power generation system extracts steam from hot water pumped from the ground, drives a steam turbine with the steam, and generates power from a generator linked to the steam turbine. At this time, the gas such as carbon dioxide, hydrogen sulfide, and sulfur dioxide dissolved in the hot water (hereinafter referred to as the gas such as hydrogen sulfide) is released into the atmosphere, so that the foul odor spreads to the surroundings. It causes problems that corrode equipment and destroy the ecosystem. In response to the problem that gas such as hydrogen sulfide spreads a foul odor to the surroundings, corrodes equipment, and destroys the ecosystem, in the conventional geothermal power generation system, hydrogen sulfide is added to the cooling water that circulates between the cooling tower and the water recovery device. Etc. are absorbed and this cooling water is returned to the ground, or a desulfurization device is installed to recover the gas such as hydrogen sulfide, but the total amount of the generated gas such as hydrogen sulfide is carried out. It is difficult to recover the hydrogen sulfide, and the unrecovered gas such as hydrogen sulfide is released into the atmosphere. It is desirable to provide a geothermal power generation system that does not release gas such as hydrogen sulfide to the atmosphere, and at this time, it is an issue that the amount of power generation is not reduced.

The problem of providing a geothermal power generation system that does not release gas such as hydrogen sulfide to the atmosphere is solved by recovering only the retained heat of hot water pumped from the ground and returning it to the ground without changing the composition.
For this reason, the Rankine cycle, which consists of a steam generator, steam turbine, condenser, etc., is a closed system, and the energy transfer medium is the Japanese Industrial Standard JIS B 8223 "Boiler Water Supply and Boiler Water Quality". Use boiler water that meets the standards. The water in this energy transfer medium circulates in a steam generator, a steam turbine, a condenser, etc. while converting to steam / water. At this time, the problem of reducing the amount of power generated by changing from the open system to the closed system used in the conventional flash geothermal power generation system is solved by using a second-class absorption heat pump from the ground. The solution is to recover the heat possessed by the pumped hot water to create a high-temperature heat source and make it possible to generate high-temperature, high-pressure steam.

In the geothermal power generation system of this embodiment, since the release of gas such as hydrogen sulfide dissolved in the hot water pumped up from the ground to the atmosphere is eliminated, the effect of eliminating the diffusion of foul odors to the surroundings and the destruction of the ecosystem is eliminated. Is obtained. Further, since the steam turbine, the condenser and the like do not come into contact with a gas such as hydrogen sulfide, corrosion resistance measures are not required, and the effect of reducing the equipment cost can be obtained. In addition, a second-class absorption type heat pump is used to recover the retained heat of hot water pumped from the ground to create a high-temperature heat source, and this high-temperature heat source is used to generate steam and supply it to the steam turbine. By increasing the temperature and pressure of the steam, the problem of reducing the amount of power generation is reduced, and the effect of improving the thermal efficiency of the steam turbine and enabling the increase in the amount of power generation can be obtained without supplying energy from outside the system. .. In addition, since the pressure of the steam supplied to the steam turbine increases, it becomes possible to adopt a reheating system, which increases the dryness of the steam in the steam turbine and causes erosion in the steam turbine and the like. The effect of suppressing In addition, since the condenser does not emit gas such as hydrogen sulfide, the steam turbine outlet pressure can be set lower than the atmospheric pressure, the thermal efficiency of the steam turbine is improved, and the amount of power generated can be increased. The effect of In addition, since the thermal efficiency of the steam turbine is improved, it is possible to reduce the amount of hot water pumped from the ground, and it is possible to obtain the effect of recovering the power plant where the amount of hot water is depleted and the amount of power generation is reduced.

Hereinafter, description will be made with reference to the drawings. The geothermal power generation system that does not release gas such as hydrogen sulfide in the hot water of Example 4 shown in FIG. 4 generally includes a power generation device main body and a second-class absorption type heat pump. The main body of the power generation device is composed of an air-water separator 11, a steam turbine 12, a generator 15, a condenser 16, a cooling tower 17, a water supply pump 18, and the like. It is composed of 32, a regenerator 33, a condenser 34, a heat exchanger 35, a cooling tower 36, and the like.

Considering that the combination of heat medium and absorption liquid used in the absorption heat pump operates in the temperature range from room temperature to about 200 ° C, water is used as the heat medium and lithium bromide is used as the main component of the absorption liquid. A combination of an aqueous solution to which a rust agent is added (hereinafter referred to as a lithium bromide aqueous solution) is used. Other combinations of heat medium and absorption liquid other than the combination of water and lithium bromide aqueous solution include a combination of water and sulfuric acid aqueous solution, ammonia and water, etc., but in the present invention, the combination of water and lithium bromide aqueous solution will be described. ..

The water S14 for the boiler is supplied into the steam separator 11 by the water supply pump 18. The water in the steam separator 11 circulates in the conduit 24 between the steam separator 11 and the absorber 32, is heated in the absorber 32, boils, and becomes hot water W14 in a steam-water mixed state. It is returned to the air-water separator 11 and separated into steam and hot water.

The steam S11 separated inside the steam separator 11 is supplied to the steam turbine 12 to drive the steam turbine 12, and itself becomes low-temperature low-pressure steam S13 and is supplied to the condenser 16 to provide cooling water. It is cooled by C11, condensed, and returned to water S14 for the boiler.

In the evaporator 31 of the second-class absorption heat pump, the water in the vessel is boiled to steam by heating the hot water W11 pumped from the ground, and this steam is the lithium bromide aqueous solution in the absorber 32 at the same pressure. Is absorbed by. In the absorber 32, the hot water W14 from the steam separator 11 is heated and boiled by the absorbed heat generated when the steam is absorbed. The lithium bromide aqueous solution in the absorber 32 that has absorbed the steam from the evaporator 31 is supplied into the regenerator 33 via the heat exchanger 35, and is boiled by heating the hot water W14 in the regenerator 33 to be boiled in the absorber 33. The vapor absorbed in 32 is released. Then, it is returned to the absorber 32 via the heat exchanger 35. The steam generated from the lithium bromide aqueous solution by boiling in the regenerator 33 is cooled by the cooling water C12 in the condenser 34 at the same pressure and returned to water, and this water is returned to the evaporator 31.

Between the evaporator 31 and the absorber 32, the heat taken from the hot water W11 pumped from the ground in the evaporator 31 is used for heating and boiling the hot water W14 in the absorber 32. Between the regenerator 33 and the condenser 34, the heat used for the regeneration of the lithium bromide aqueous solution (recovery of the lithium bromide concentration of the lithium bromide aqueous solution and the production of water to the evaporator 31) in the regenerator 33 is condensed. Heat is transferred to the cooling water C12 in the vessel 34, transferred to the cooling tower 36 by the cooling water C12, and discharged from the cooling tower 36 into the atmosphere.

Hot water W11 containing a gas such as hydrogen sulfide pumped up from the ground flows through the conduit 21 connecting the production well V11 and the evaporator 31 of the second-class absorption type heat pump, is introduced into the evaporator 31, and evaporates. Heat is deprived by the vessel 31, then flows through the conduit 22 connecting the evaporator 31 and the regenerator 33, is introduced into the regenerator 33, is deprived of heat by the regenerator 33, and then the regenerator 33 and the reduction well. It flows through the conduit 23 connecting X11 and is returned to the ground from the reduction well X11.

Therefore, in the geothermal power generation system of the present embodiment, the hot water W11 containing a gas such as hydrogen sulfide pumped up from the ground is deprived of the retained heat and its temperature drops, but it is not released to the atmosphere. Since it is returned to the ground without changing the flow rate and composition, the effect of preventing gas such as hydrogen sulfide from being discharged into the atmosphere can be obtained.

Further, at this time, by adopting the second type absorption type heat pump, the temperature of the steam S11 supplied to the steam turbine 12 is higher than the temperature of the hot water W11 pumped from the ground without receiving energy supply from outside the system. Since the steam pressure at the inlet of the steam turbine 12 becomes higher than the atmospheric pressure, the effect of improving the thermal efficiency of the steam turbine 12 can be obtained.

Further, since the Rankine cycle of the water closing system makes it possible to lower the pressure at the outlet of the steam turbine 12 below the atmospheric pressure, the effect of improving the thermal efficiency of the steam turbine 12 can be obtained.

However, when the inlet pressure of the steam turbine 12 rises and the outlet pressure drops, the steam in the steam turbine 12 becomes moist steam, and water droplets are generated in the steam, and the water droplets cause erosion of the turbine blades and the like. The problem of being eroded occurs. The problem that the steam in the steam turbine 12 becomes moist steam and the blades and the like of the steam turbine 12 are eroded is that a superheater or a reheater is installed to make the steam supplied to the steam turbine 12 superheated steam. , The solution is to improve the dryness of the steam in the steam turbine 12.

The geothermal power generation system that does not release gas such as hydrogen sulfide to the atmosphere having a reheater for explaining Example 5 of the present invention shown in FIG. 5 is a steam generated from a steam separator 41 by having a second-class absorption type heat pump. Utilizing the fact that S41 has a high temperature and high pressure, the steam turbine is divided into a high pressure side steam turbine 42 and a low pressure side steam turbine 44, and a reheater 43 is installed between the steam turbines 42 and 44.

The geothermal power generation system having the reheater 43 and not releasing gas such as hydrogen sulfide to the atmosphere is composed of a power generation device main body and a second-class absorption heat pump. The main body of the power generator is composed of an air-water separator 41, steam turbines 42 and 44, a reheater 43, a generator 45, a condenser 46, a cooling tower 17, a water supply pump 18, and the like. , Evaporator 61, absorber 62, condenser 63, condenser 64, heat exchanger 65, cooling tower 66 and the like.

The water S44 for the boiler described above is supplied into the steam separator 41 by the water supply pump 48, and the water in the steam separator 41 circulates between the steam separator 41 and the absorber 62, and the absorber 62 The hot water W44 is heated and returned to the gas-water separator 41, and is internally separated into steam and water.

The high-temperature and high-pressure steam S41 separated inside the steam separator 41 is supplied to the steam turbine 42 to drive the steam turbine 42, and itself becomes medium-temperature and medium-pressure steam, which is supplied to the reheater 43. NS. The steam supplied to the condenser 43 is heated by the steam inside the steam separator 41 to become high-temperature medium-pressure steam S42, which is supplied to the low-pressure steam turbine 44, drives the steam turbine 44, and operates itself. Becomes low-temperature low-pressure steam S43, is supplied to the condenser 16, is cooled by the cooling water C41, condenses, and returns to the boiler water S44.

In the evaporator 61 of the second-class absorption heat pump, the water in the vessel is boiled to steam by heating the hot water W41 pumped from the ground, and this steam is the lithium bromide aqueous solution in the absorber 62 at the same pressure. Is absorbed by. In the absorber 62, the hot water W44 from the steam separator 41 is heated and boiled by the absorbed heat generated when the steam is absorbed. The lithium bromide aqueous solution in the absorber 62 that has absorbed the steam from the evaporator 61 is supplied into the regenerator 63 via the heat exchanger 65, and is boiled by heating the hot water W41 in the regenerator 63 to be boiled in the absorber 63. The vapor absorbed in 62 is released. Then, it is returned to the absorber 62 via the heat exchanger 65. The steam generated from the lithium bromide aqueous solution by boiling in the regenerator 63 is cooled by the cooling water C42 in the condenser 64 at the same pressure, condensed, and returned to the boiler water S44.

Between the evaporator 61 and the absorber 62, the heat taken from the hot water W41 pumped from the ground in the evaporator 61 is used in the absorber 62 to heat the hot water W44. Between the regenerator 63 and the condenser 64, the heat used for regenerating the lithium bromide aqueous solution in the regenerator 63 is transferred to the cooling water C42 in the condenser 64 and transferred to the cooling tower 66 by the cooling water C42. , Is released into the atmosphere from the cooling tower 66.

Hot water W41 containing a gas such as hydrogen sulfide pumped up from the ground flows through the conduit 51 connecting the production well V41 and the evaporator 61 of the second-class absorption type heat pump, is introduced into the evaporator 61, and evaporates. Heat is deprived by the vessel 61, then flows through the conduit 52 connecting the evaporator 61 and the regenerator 63, is introduced into the regenerator 63, is deprived of heat by the regenerator 63, and then the regenerator 63 and the reduction well. It flows through the conduit 53 connecting X41 and is returned to the ground from the reduction well X41.

Table 2 below shows an example of steam specifications in the geothermal power generation system of Example 1 and Example 2 of the present invention under the condition that the temperature of hot water pumped from the ground is 150 ° C. by desk calculation.

The dryness of the steam turbine outlet steam is 79% in the geothermal power generation system that does not release gas such as hydrogen sulfide in Example 1 of the present invention to the atmosphere, but in Example 2 of the present invention, the steam turbine 42 on the high pressure side The outlet is 90%, and the outlet of the steam turbine 44 on the low pressure side is 91%. As a result, in the geothermal power generation system that does not release a gas such as hydrogen sulfide in Example 2 of the present invention to the atmosphere, the dryness of the steam at the outlet of the steam turbine is improved, and the effect of suppressing erosion can be obtained. Further, the turbine output per 1 kg of steam supplied from the steam turbine is 158 kJ / kg in the geothermal power generation system that does not release gas such as hydrogen sulfide in Example 1 of the present invention to the atmosphere, whereas it is 179 kJ / kg in Example 2 of the present invention. And 21kJ / kg increase. As a result, the geothermal power generation system that does not release a gas such as hydrogen sulfide according to the second embodiment of the present invention to the atmosphere has an effect that the amount of power generation can be increased.

According to this embodiment, a steam separator (11), a steam turbine (12) to which steam emitted from the steam separator (11) is supplied, and a generator (15) interlocking with the steam turbine (12). , A water condensing device (16) in which the steam discharged from the steam turbine (12) is condensed, and a water supply pump (18) for supplying the water condensed by the water condensing device (16) to the air-water separator (11). Type 2 absorption heat pump with evaporator (31), absorber (32), regenerator (33), condenser (34), heat exchanger (35) and cooling tower (36), heat from the ground The conduit (21) that guides water from the production well to the type 2 absorption heat pump, the conduit (23) that guides the hot water from the type 2 absorption heat pump to the reduction well, the air-water separator (11) and the above. By providing a conduit (24) through which hot water circulating between the absorbers (32) flows, gas such as hydrogen sulfide dissolved in hot water pumped up from the ground is provided. Since there is no release to the atmosphere, the effect of eliminating the spread of foul odors to the surroundings and the destruction of the ecosystem can be obtained.

A steam separator (41) having a reheater (43) inside, a steam turbine (42) to which steam discharged from the steam separator (41) is supplied, and steam discharged from the steam turbine (42). The reheater (43) to which the water is supplied, the steam turbine (44) to which the steam emitted from the reheater (43) is supplied, and the generator (45) interlocking with these steam turbines (42 and 44). The latter water condensing device (46) in which the steam discharged from the steam turbine (44) is condensed, and the water supply pump (48) that supplies the water condensed by the water condensing device (46) to the air-water separator (41). , A second-class absorption heat pump with an evaporator (61) and a absorber (62) and a regenerator (63) and a condenser (64) and a heat exchanger (65) and a cooling tower (66), from the ground. A conduit (51) that guides hot water from a production well to the type 2 absorption type heat pump, a conduit (53) that guides hot water from the type 2 absorption type heat pump to a reduction well, and the air-water separator (41). A gas such as hydrogen sulfide dissolved in hot water pumped up from the ground by providing a conduit (54) through which hot water circulating between the absorbers (62) flows. Since the release of heat to the atmosphere is eliminated, the effect of eliminating the spread of foul odors to the surroundings and the destruction of the ecosystem can be obtained.

This embodiment relates to a geothermal power generation system that suppresses erosion, particularly a geothermal power generation system having a type 2 absorption type heat pump. In the flash geothermal power generation system used in many conventional geothermal power plants, the steam supplied to the steam turbine is saturated steam separated from the hot water in the air-water mixed state pumped from the ground. be. Therefore, in the steam turbine, the temperature and pressure of the saturated steam decrease to become moist steam, and water droplets are generated inside the steam, and the generated water droplets have a problem of causing erosion (erosion). Further, in the geothermal power generation system having the type 2 absorption type heat pump described in the prior art document: Japanese Patent Application Laid-Open No. 2014-134106, the steam supplied to the steam turbine is heated by the type 2 absorption type heat pump and boiled. Since it is saturated steam, there is a problem that in the steam turbine, the temperature and pressure of the saturated steam decrease to become moist steam, water droplets are generated inside the steam, and erosion is generated. When erosion occurs, vibration, noise, and the like are generated in the steam turbine, and when this erosion progresses, there is a problem that the steam turbine and peripheral equipment of the steam turbine are damaged. The problem to be solved by this embodiment is to provide a geothermal power generation system that suppresses erosion having a second-class absorption heat pump.

Providing a geothermal power generation system with a Type 2 absorption heat pump that suppresses erosion by changing the steam supplied to the steam turbine from saturated steam to superheated steam and increasing the dryness of the steam in the steam turbine. solve. To change the steam supplied to the steam turbine from saturated steam to superheated steam, a second-class absorption heat pump, chiller, reheater, etc. are installed, and a second-class absorption heat pump creates a high-temperature heat source. This is achieved by heating the steam flowing through the tube of the superheater and the tube of the reheater using a hot heat source. When the steam supplied to the steam turbine is superheated steam and the steam at the turbine outlet is also superheated steam, the steam in the turbine becomes steam that does not contain water droplets, so that erosion does not occur and the problem is solved. .. In addition, industrially, even if the steam in the steam turbine is moist steam, the dryness of the steam at the turbine outlet (moisture weight in steam / air-water mixed steam weight) is 90% or more (wetness 10% or less, If the degree of wetness = 100% − degree of dryness), the amount of water droplets generated in the steam becomes small, so that the erosion becomes weak and the influence of the erosion is ignored.

When the erosion disappears or becomes negligible according to this embodiment, the material of the moving blade, the stationary blade, the shaft, and the casing of the steam turbine is changed from the erosion resistant material (for example, CrMoV steel, NiCrMoV steel) to an inexpensive carbon steel. This makes it possible to reduce material costs. In addition, the deterioration rate of the moving blades, stationary blades, shafts, and casing of the steam turbine is slowed down, and the life of the equipment is extended, so that the effect of reducing maintenance costs can be obtained. Further, since the steam flow in the turbine is stabilized, the effect of eliminating the decrease in thermal efficiency due to the unstable steam flow and the effect of suppressing vibration and noise can be obtained. Further, when vibration and noise are suppressed, the capacity of the steam turbine can be increased, and the effect of reducing the equipment cost due to economies of scale can be obtained.

FIG. 6 is a schematic view of a geothermal power generation system that suppresses erosion in which a superheater 27 and a reheater 28 are installed to explain the sixth embodiment of the present invention. Generally, a geothermal power generation device main body and a second-class absorption heat pump It is composed of. The main body of the geothermal power generation device is composed of an air-water separator 11 having a steam generator 26, a superheater 27, and a reheater 28, steam turbines 13 and 14, a generator 15, a condenser 16, a cooling tower 17, and the like. The absorption heat pump is composed of an evaporator 31, an absorber 32, a condenser 33, a condenser 34, a heat exchanger 35, a cooling tower 36, and the like.

Considering that the combination of heat medium and absorption liquid used in the absorption heat pump operates in the temperature range from room temperature to about 200 ° C, water is used as the heat medium and lithium bromide is used as the main component of the absorption liquid. A combination of an aqueous solution to which a rust agent is added (hereinafter referred to as a lithium bromide aqueous solution) is used. In addition to the combination of water and lithium bromide aqueous solution, there are combinations of water and sulfuric acid aqueous solution, and ammonia and ammonia water. In the present invention, the combination of water and lithium bromide aqueous solution will be described.

The hot water W12 branched from the hot water W11 pumped from the ground flows in the conduit 22 and is supplied to the steam generator 26 in the air-water separator 11. Hot water W14 circulates in the conduit 24 between the air-water separator 11 and the absorber 32 of the absorption type heat pump, and the hot water W14 is heated and boiled in the absorber 32 to become steam and hot water. It is returned to the air-water separator 11. In the steam separator 11, the hot water or steam in the vessel heats the hot water W12 in the steam generator 26 pipe and converts it into steam. The steam generated from the pipe of the steam generator 26 flows through the pipe of the superheater 27, and at this time, is heated from the hot water or steam in the steam separator 11 to become superheated steam S11 and is supplied to the steam turbine 13. , Drives the steam turbine 13 and turns itself into medium-temperature, medium-pressure steam. The steam at medium temperature and medium pressure is supplied to the reheater 28, and at this time, it is heated by hot water or steam in the steam separator 11 to become superheated steam S12 with high temperature and medium pressure, and is supplied to the steam turbine 14. Then, the steam turbine 14 is driven, and itself becomes low-temperature low-pressure steam S13. The low-temperature low-pressure steam S13 is supplied to the condenser 16, cooled by the cooling water C11, condensed, and mixed with the cooling water C11. The flow rate of the cooling water C11 is increased by mixing the condensed water of the steam S13, and the increment of the cooling water C11 is returned to the ground from the reduction well X12.

The hot water W13 branched from the hot water W11 pumped from the ground flows through the conduit 23 and is deprived of heat by the evaporator 31 and the regenerator 33 of the second-class absorption heat pump, and then goes underground from the reduction well X11. Returned to.

In the evaporator 31 of the second-class absorption heat pump, the water in the vessel is boiled into steam by heating the hot water W14, and this steam is absorbed by the lithium bromide aqueous solution in the absorber 32 at the same pressure. In the absorber 32, the hot water W14 circulating between the steam separator 11 and the absorber 32 is heated and boiled by the absorbed heat generated when the steam is absorbed. The lithium bromide aqueous solution in the absorber 32 that has absorbed the steam from the evaporator 31 is supplied into the regenerator 33 via the heat exchanger 35, and is heated in the regenerator 33 by the hot water W13 that has passed through the evaporator 31. It boils and releases the vapor absorbed in the absorber 32. Then, it is returned to the absorber 32 via the heat exchanger 35. The steam generated by boiling in the regenerator 33 is cooled by the cooling water C12 in the condenser 34 at the same pressure and returned to water, and this water is returned to the evaporator 31.

Between the evaporator 31 and the absorber 32, the heat taken from the hot water W13 in the evaporator 31 is used for heating and boiling the hot water W14 in the absorber 32. Between the regenerator 33 and the condenser 34, the heat used for the regeneration of the lithium bromide aqueous solution (recovery of the lithium bromide concentration of the lithium bromide aqueous solution and the production of water to the evaporator 31) in the regenerator 33 is condensed. Heat is transferred to the cooling water C12 in the vessel 34, transferred to the cooling tower 36 by the cooling water C12, and discharged from the cooling tower 36 into the atmosphere.

By installing the superheater 27, the steam S11 supplied to the steam turbine 13 on the high pressure side becomes superheated steam, and the steam in the steam turbine 13 becomes superheated steam or wet steam with increased dryness. Further, by installing the reheater 28, the steam S12 supplied to the low-pressure steam turbine 14 becomes superheated steam, and the steam in the steam turbine 14 becomes superheated steam or wet steam with increased dryness. ..

Therefore, since water droplets disappear or become small in the steam in the steam turbines 13 and 14, the effect of suppressing erosion can be obtained.

However, if the superheater 27 and the reheater 28 are made excessively large to increase the degree of superheat of the steam supplied to the steam turbine, the saturated steam temperature is lowered due to the limitation of the maximum steam temperature, and the steam pressure is lowered to steam. The thermal efficiency of the turbine is reduced, which causes a problem that the amount of power generated is reduced.

The problem that the amount of power generation is reduced due to excessive suppression of erosion is solved by allowing the dryness of steam at the outlet of the steam turbine to be reduced to about 90% under conditions where erosion can be ignored.

Allowing the dryness of steam at the outlets of steam turbines 13 and 14 to be reduced to 90% makes it possible to eliminate the superheater and make the steam supplied to the steam turbine on the high pressure side saturated steam. As a result, the steam generator and superheater in the steam separator are not required, the equipment cost is reduced, erosion can be ignored, and an economical geothermal power generation system that increases the amount of power generated can be provided. Be done.

FIG. 7 is a schematic diagram of a geothermal power generation system that suppresses erosion to explain Example 7 of the present invention. Generally, from the above-mentioned geothermal power generation system of Example 6 of the present invention, a reheater is left and an evaporator is used. And it is a geothermal power generation system with the superheater removed.

The hot water W42 branched from the hot water W41 pumped from the ground flows in the conduit 52 and is supplied to the steam separator 41. Hot water W44 circulates in the conduit 54 between the air-water separator 41 and the absorber 62 of the absorption type heat pump, and the hot water W44 is heated and boiled in the absorber 62 to become steam and hot water. It is returned to the air-water separator 41 and separated into steam and hot water. The separated steam S41 is supplied to the steam turbine 43, drives the steam turbine 43, and becomes steam at medium temperature and medium pressure. The steam at medium temperature and medium pressure is supplied to the reheater 58 and heated by the hot water or steam in the steam separator 41 to become superheated steam S42 at high temperature and medium pressure. The superheated steam S42 that has become high temperature and medium pressure is supplied to the steam turbine 44 to drive the steam turbine 44, and itself becomes low temperature and low pressure steam S43, is supplied to the condenser 46, and is cooled by the cooling water C41. Condensed and mixed with cooling water C41. By mixing the condensed water of the steam S43, the amount of the cooling water C41 is increased, and the increment is returned to the ground from the reduction well X42.

The hot water W43 branched from the hot water W41 pumped from the ground flows through the conduit 53 and is introduced in the order of the evaporator 61 and the regenerator 63 of the second-class absorption heat pump, and after the retained heat is deprived, It is returned to the ground from the reduction well X41.

Between the evaporator 61 and the absorber 62 of the second-class absorption heat pump, the heat taken by the hot water W43 in the evaporator 61 is used for heating and boiling the hot water W44 in the absorber 62. Between the regenerator 63 and the condenser 64, the heat used for regenerating the lithium bromide aqueous solution in the regenerator 63 is transferred to the cooling water C52 in the condenser 64 and transferred to the cooling tower 66 by the cooling water C42. It is released into the atmosphere from the cooling tower 66.

FIG. 8 shows a model steam diagram of the entropy enthalpy of the steam of the geothermal power generation system that suppresses erosion shown in Examples 6 and 7 of the present invention.

The inlet steam and outlet steam of the steam turbine 13 on the high pressure side in Example 6 of the present invention shown in FIG. 8 are shown at points A and B, and the inlet steam and outlet steam of the steam turbine 14 on the low pressure side are designated as points C. The inlet steam and outlet steam of the steam turbine 43 on the high pressure side in Example 7 are indicated by points A'and B', and the inlet steam and outlet steam of the steam turbine 44 on the low pressure side are indicated by points C. Indicated by point D.

On the other hand, in a geothermal power generation system having a type 2 absorption type heat pump that does not take measures against erosion, the steam at the outlet of the steam turbine is represented by a point P or a point P', and becomes a wet steam with a reduced dryness. At this time, it is presumed that many water droplets are generated in the wet steam whose dryness has decreased, and remarkable erosion is generated in the steam turbine.

Table 2 shows an example of the steam specifications of the geothermal power generation system that suppresses erosion having the Type 2 absorption heat pump shown in Examples 6 and 7 of the present invention by desk calculation ignoring energy loss. Under the condition of using hot water pumped from the ground at 150 ° C. and 0.48 MPa, the dryness of the outlet steam of the steam turbine 13 on the high pressure side in Example 6 of the present invention shown in FIG. 6 is 97.0% and low pressure. The dryness of the outlet steam of the steam turbine 14 on the side is 95.0%, which is 90% or more, and water droplets are generated in the steam inside the steam turbines 13 and 14 on the high pressure side and the low pressure side. Enter the conditions that do not cause any problems.

At this time, the theoretical output of the high-pressure steam turbine 13 per 1 kg of steam is 138 kJ / kg, the theoretical output of the low-pressure steam turbine 14 is 277 kJ / kg, and the total theoretical output is 415 kJ / kg.

In Example 2 of the present invention shown in FIG. 7, the dryness of the outlet steam of the steam turbine 43 on the high pressure side is 92.0%, and the dryness of the outlet steam of the steam turbine 44 on the low pressure side is 95.0%. It becomes 90% or more, and water droplets are generated in the steam inside the steam turbines 43 and 44 on the high pressure side and the low pressure side, but the condition does not cause the problem of erosion.

At this time, the theoretical output of the high-pressure steam turbine 43 per 1 kg of steam is 218 kJ / kg, the theoretical output of the low-pressure steam turbine 44 is 277 kJ / kg, and the total theoretical output is 495 kJ / kg. The total theoretical output of Example 2 of the present invention is 80 kJ / kg larger than the total theoretical output of Example 1 of the present invention.

In short, in the geothermal power generation system that suppresses erosion in which only the reheater of Example 7 of the present invention shown in FIG. 7 is installed, the steam generator, the superheater description, and the reheater shown in FIG. 6 are installed. Compared with the geothermal power generation system that suppresses erosion in Example 6 of the present invention, the dryness of the steam at the steam turbine outlet on the high pressure side is reduced, so that erosion is likely to occur, but the dryness of the steam at the turbine outlet is 90%. By allowing it to drop to, erosion can be ignored and the effect of increasing the output of the steam turbine can be obtained.

Further, the geothermal power generation system that suppresses erosion in which only the reheater of the seventh embodiment of the present invention shown in FIG. 7 is installed does not require a steam generator and a superheater, which has an economic effect of reducing the equipment cost. Is obtained.

In this embodiment, steam from the steam generator (26), the steam separator (27), the steam separator (11) having the reheater (28), and the steam generator (26) is supplied. The superheater (27), the steam turbine (13) to which the steam discharged from the superheater (27) is supplied, and the reheater (28) to which the steam discharged from the steam turbine (13) is supplied. The steam turbine (14) to which the steam discharged from the reheater (28) is supplied, the generator (15) interlocking with the steam turbines (13 and 14), and the steam discharged from the steam turbine (14) are supplied. A second type having a steamer (16), an evaporator (31), an absorber (32), a regenerator (33), a condenser (34), a heat exchanger (35), and a cooling tower (36). Absorption type heat pump, conduit (23) for guiding the hot water pumped from the ground to the evaporator (31), hot water circulating between the steam separator (11) and the absorber (32) flows. It is characterized by having a conduit (24).

Further, in this embodiment, a steam separator (41) having a superheater (58) inside, a steam turbine (43) to which steam emitted from the steam separator (41) is supplied, and this steam turbine ( A reheater (58) to which steam discharged from 43) is supplied, a steam turbine (44) to which steam discharged from this reheater (58) is supplied, and power generation linked with the steam turbines (43 and 44). Machine (45), water condenser (46), evaporator (61) and absorber (62) and regenerator (63) and condenser (64) to which steam discharged from the steam turbine (44) is supplied. A second-class absorption type heat pump having a heat exchanger (65) and a cooling tower (66), a conduit (53) for guiding hot water pumped from the ground to the evaporator (61), and a steam separator (41). ) And a conduit (54) through which hot water circulating between the absorber (62) flows.

When the erosion disappears or becomes negligible according to this embodiment, the material of the moving blade, the stationary blade, the shaft, and the casing of the steam turbine is changed from the erosion resistant material (for example, CrMoV steel, NiCrMoV steel) to an inexpensive carbon steel. This makes it possible to reduce material costs. Further, according to this embodiment, the deterioration rate of the moving blades, the stationary blades, the shaft, and the casing of the steam turbine is slowed down, and the life of the apparatus is extended, so that the effect of reducing the maintenance cost can be obtained. Further, according to this embodiment, since the steam flow in the turbine is stabilized, the effect of eliminating the decrease in thermal efficiency due to the unstable steam flow and the effect of suppressing vibration and noise can be obtained. Further, according to this embodiment, when vibration and noise are suppressed, the capacity of the steam turbine can be increased, and the effect of reducing the equipment cost due to economies of scale can be obtained.

In the event of an electrical accident such as a ground fault or short circuit accident, related electrical equipment and facilities are required to stop power generation and transmission without delay in order to prevent the spread of the electrical accident. However, since the geothermal power generation system of the prior art is operated with a large amount of retained heat, even if the power generation is stopped when an emergency power failure occurs during the power generation operation, the heat is dissipated until the retained heat is small. An operation to continue the operation (hereinafter referred to as a power failure mode operation) is performed. In a geothermal power generation system having a type 2 absorption type heat pump, the heat of dilution of the absorbing liquid is added to the heat possessed by the power generation device and the type 2 absorption type heat pump. , Has the problem of large pressure rise. However, the geothermal power generation system with a second-class absorption heat pump disclosed in the prior art literature has an operating method that safely discharges retained heat and dilution heat to solve the problem of pressure rise when power generation is stopped urgently. Not specified.

The challenge is to create a second-class absorption heat pump that discharges the heat held in the geothermal power generation system and the heat of dilution of the lithium bromide aqueous solution to enable safe power failure mode operation when power generation is stopped urgently due to an electrical accident. The purpose is to provide a geothermal power generation system to have.

The challenge of providing a geothermal power generation system with a second-class absorption heat pump that discharges the heat held in the geothermal power generation system and the heat of dilution of the lithium bromide aqueous solution to the outside of the system and enables safe operation in a power failure mode is a power failure. When operating the mode, it is solved by adding an exhaust heat route that can exhaust the retained heat in the geothermal power generation system and the heat of dilution of the lithium bromide aqueous solution to the outside of the system without delay. In addition, the exhaust heat route that discharges the heat held in the geothermal power generation system and the heat of dilution of the lithium bromide aqueous solution to the outside of the system is between the air-water separator of the geothermal power generation system and the absorber of the second-class absorption heat pump. It is a heat transfer route that uses circulating hot water and then uses the cooling water of the cooling tower in the Type 2 absorption heat pump to dissipate heat from the cooling tower to the atmosphere. This exhaust heat route is not used during power generation mode operation, but is used during power failure mode operation.

When stopping power generation, it is possible to switch to power failure mode without delay and dissipate the heat held in the geothermal power generation system and the heat of dilution of the lithium bromide aqueous solution to the outside of the system. The effect of eliminating damage can be obtained. The geothermal power generation system with a second-class absorption type heat pump has a feature of higher power generation efficiency than the conventional flash type geothermal power generation, and it is possible to generate power with a small amount of hot water pumped from the ground. Therefore, the present invention has the effect of providing a safe, compact, and economical geothermal power generation system with high output.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. A geothermal power generation system having a second-class absorption heat pump for safe emergency stop of a closed Rankine cycle, which describes Example 8 of the present invention shown in FIG. 9, generally combines a geothermal power generation device main body and a second-class absorption heat pump. It has a similar configuration. The main body of the geothermal power generation device is composed of a gas-water separator 11, a steam turbine 12, a generator 13, a condenser 14, a cooling tower 15, a water supply pump 16, and the like, and boiler water enters the gas-water separator 11. ing. The second-class absorption heat pump is composed of an evaporator 31, an absorber 32, a regenerator 33, a condenser 34, a heat exchanger 35, a cooling tower 36, and the like. The air-water separator 11 of the main body of the geothermal power generation device and the absorber 32 of the second-class absorption heat pump are connected by a conduit 24 through which hot water W14 circulates.

Then, a heat exchanger 41 is installed, and in the heat exchanger 41, the hot water W14 circulating between the air-water separator 11 and the absorber 32 and the cooling water circulating between the condenser 34 and the cooling tower 36 are installed. Heat exchange C12. The hot water W14 to the heat exchanger 41 flows through the conduit 27 branched from the conduit 24 and is introduced, and the cooling water C12 flows through the conduit 28 branched from the conduit 26 and is introduced. Valves 43, 44, and 45 for switching the flow path are installed at the connection between the conduit 24 and the conduit 27 through which the hot water W14 flows, and at the connection between the conduit 26 and the conduit 28 through which the cooling water C12 flows, for switching the flow path. Valves 47, 48 and 49 are installed.

The flow path through which the hot water W14 circulates between the steam separator 11, the absorber 32, and the heat exchanger 41 is a bypass of the flow path that circulates between the steam separator 11 and the absorber 32. The flow path through which the cooling water C12 circulates between the condenser 34, the heat exchanger 41, and the cooling tower 36 serves as a bypass for the flow path that circulates between the air-water separator 11 and the absorber 32. Hot water W14 or cooling water C12 flows through these bypass flow paths only during power failure mode operation.

Considering that the combination of heat medium and absorption liquid used in the absorption heat pump operates in the temperature range from room temperature to about 200 ° C, water is used as the heat medium and lithium bromide is used as the main component of the absorption liquid. A combination of an aqueous solution to which a rust agent is added (hereinafter referred to as a lithium bromide aqueous solution) is used. In addition to the combination of water and lithium bromide aqueous solution, there is a combination of water and sulfuric acid aqueous solution, and ammonia and ammonia aqueous solution. In this embodiment, a combination of water and an aqueous solution of lithium bromide will be described. The concentration of lithium bromide in the aqueous solution of lithium bromide during operation of the absorption heat pump is 58 to 66%.

In the power generation mode operation, in the geothermal power generation device main body, the hot water in the steam separator 11 circulates in the conduit 24 between the steam separator 11 and the absorber 32 of the second-class absorption heat pump, and this heat. The water W14 is heated in the absorber 32 to boil, and is separated into hot water and steam in the returned air-water separator 11. The separated steam S11 is supplied to the steam turbine 12. The steam S11 supplied to the steam turbine 12 drives the steam turbine 12, and itself becomes low-temperature low-pressure steam S12, is supplied to the condenser 14, and is cooled and condensed by the cooling water C11. The condensed water S13 is returned to the brackish water separator 11 by the water supply pump 16. The heat generated when the steam S12 is condensed is carried to the cooling tower 15 by the cooling water C11 and discharged from the cooling tower 15 to the atmosphere.

The hot water W11 pumped from the ground flows through the conduit 21 and is introduced into the evaporator 31 of the second-class absorption heat pump. After heating the water in the evaporator 31, it is introduced into the regenerator 33 and regenerated. After heating the lithium bromide aqueous solution in the vessel 33, it is returned to the ground from the reduction well X11.

The water in the evaporator 31 is heated by the hot water W11 pumped from the ground to become steam, and this steam is absorbed by the lithium bromide aqueous solution in the absorber 32 at the same pressure. At this time, in the absorber 32, when the lithium bromide aqueous solution absorbs steam, absorption heat is generated, and the hot water W14 from the gas-water separator 11 is heated by the absorbed heat. The lithium bromide aqueous solution in the absorber 32 that has absorbed the steam is supplied into the regenerator 33 via the heat exchanger 35, and is boiled in the regenerator 33 by heating from the hot water that has passed through the evaporator 31. The vapor absorbed in 32 is released. Then, it is returned to the absorber 32 via the heat exchanger 35. The steam generated from the lithium bromide aqueous solution boiling in the regenerator 33 is cooled by the cooling water C12 in the condenser 34 at the same pressure and returned to water, and this water is returned to the evaporator 31. In the condenser 34, the heat of condensation generated when the steam from the regenerator 33 is condensed is carried to the cooling tower 36 by the cooling water C12 and discharged from the cooling tower 36 to the atmosphere.

In the operation in the power generation mode, the valve 37 on the conduit line connecting the bottom of the evaporator 31 and the absorber 32 is closed, and the valve 38 on the conduit line connecting the bottom of the condenser 34 and the regenerator 33 is closed. Water is accumulated inside the 31 and the condenser 34, and the lithium bromide aqueous solution is accumulated inside the absorber 32 and the regenerator 33.

Further, in the operation of this power generation mode, the flow path switching valves 43 and 47 are open, the flow path switching valves 44, 45, 48 and 49 are closed, and the hot water W14 is transferred to the heat exchanger 41. It circulates between the air-water separator 11 and the absorber 32 without flowing, and the cooling water C12 circulates between the condenser 34 and the cooling tower 26 without flowing to the heat exchanger 41.

When the power generation is urgently stopped due to the occurrence of an electric accident, the pumping of the hot water W11 from the ground is stopped, and the operation in the power generation mode is switched to the operation in the power failure mode without delay.

In the operation in this power failure mode, the valve 37 on the conduit connecting the bottom of the evaporator 31 and the absorber 32 is opened, and the water in the evaporator 31 is allowed to flow into the absorber 32 to cause the aqueous lithium bromide solution inside the absorber 32. To dilute. Further, the valve 38 on the conduit connecting the regenerator 33 and the bottom of the condenser 34 is opened, and the water in the condenser 34 is allowed to flow into the regenerator 33 to dilute the lithium bromide aqueous solution inside the regenerator 33. When the lithium bromide aqueous solution is diluted to 55% or less, lithium bromide does not crystallize even at room temperature. At this time, heat of dilution of lithium bromide is generated, and this heat of dilution is discharged to the outside of the system without delay in order to prevent damage due to an increase in pressure due to a temperature rise.

In this power failure mode operation, the flow path switching valves 43 and 47 are closed, and the flow path switching valves 44, 45, 48 and 49 are opened. As a result, the hot water W14 circulates between the air-water separator 11, the absorber 32, and the heat exchanger 41, and the cooling water C12 circulates between the condenser 34, the heat exchanger 41, and the cooling tower 26, and heat is generated. In the exchanger 41, heat is exchanged between the hot water W14 and the cooling water C12, and the heat held inside the air-water separator 11 is carried to the heat exchanger 41 by the hot water W14, and the cooling water in the heat exchanger 41. It is transmitted to C12, carried to the cooling tower 26 by the cooling water C12, and discharged from the cooling tower 26 into the atmosphere.

In this power failure mode operation, the flow of the lithium bromide aqueous solution in the Type 2 absorption heat pump continues the same operation as the power generation mode operation, whereby the heat of dilution of lithium bromide generated in the regenerator 33 is regenerated. It is carried to the absorber 32 by the lithium bromide aqueous solution that circulates in the vessel 33, the heat exchanger 35, and the absorber 32. The heat of dilution of lithium bromide in the absorber 32 and the heat of dilution of lithium bromide in the regenerator 33 carried to the absorber 32 are transferred to the hot water W14 and carried to the heat exchanger 41 by the hot water W14. , It is transmitted to the cooling water C12 in the heat exchanger 41, carried to the cooling tower 26 by the cooling water C12, and discharged from the cooling tower 26 into the atmosphere.

In short, according to the present invention, when the power generation is urgently stopped due to an electric accident, the heat possessed by the apparatus and the heat of dilution of the lithium bromide aqueous solution can be discharged to the outside without delay. The effect of suppressing damage due to increased pressure can be obtained.

Example 1 of the present invention shown in FIG. 9 is a closed Rankine cycle geothermal power generation system that generates electricity with steam generated from high-purity boiler water, but hot water pumped from underground containing a corrosive gas such as hydrogen sulfide. It can also be applied to an open Rankine cycle geothermal power generation system that generates electricity from steam generated from.

A geothermal power generation system having a second-class absorption heat pump that employs an open Rankine cycle to explain Example 9 of the present invention shown in FIG. 10 and has a second-class absorption heat pump is generally a geothermal power generation device main body and a second-class absorption heat pump. The main body of the geothermal power generation device is composed of a gas-water separator 51, a steam turbine 52, a generator 53, a water recovery device 54, a cooling tower 55, and others. , Evaporator 71, absorber 72, regenerator 73, condenser 74, heat exchanger 75, cooling tower 76, etc. In this geothermal power generation device main body and type 2 absorption heat pump, hot water W54 circulates. It is connected by a conduit 64.

Then, a heat exchanger 81 is installed, and in this heat exchanger 81, the hot water W54 circulating between the air-water separator 51 and the absorber 72 and the cooling water C52 circulating between the condenser 74 and the cooling tower 76 are installed. Is exchanging heat. The hot water W54 to the heat exchanger 81 flows through the conduit 67 branched from the conduit 64 and is introduced, and the cooling water C52 flows through the conduit 68 branched from the conduit 66 and is introduced. Valves 83, 84, and 85 for switching the flow path are installed at the connection between the conduit 64 and the conduit 67 through which the hot water W54 flows, and at the connection between the conduit 66 and the conduit 68 through which the cooling water C52 flows, for switching the flow path. Valves 87, 88 and 89 are installed.

The flow path that circulates between the air-water separator 51, the absorber 72, and the heat exchanger 81 through which the hot water W54 flows becomes a bypass flow path of the flow path that circulates between the air-water separator 51 and the absorber 72. The flow path that circulates between the condenser 74, the heat exchanger 71, and the cooling tower 76 through which the cooling water C52 flows becomes a bypass flow path of the flow path that circulates between the air-water separator 51 and the absorber 72. Hot water W54 or cooling water C52 flows through these bypass paths only during power failure mode operation.

In the operation in the power generation mode, the hot water W52 branched from the hot water W51 pumped from the ground is supplied to the air-water separator 51. The hot water in the air-water separator 51 circulates in the conduit 62 between the air-water separator 51 and the absorber 72 of the second-class absorption heat pump, and is heated and boiled in the absorber 72. It becomes W54, is returned to the air-water separator 51, and is separated into hot water and steam. The separated steam S51 is supplied to the steam turbine 52. The steam S51 supplied to the steam turbine 52 drives the steam turbine 52, and itself becomes low-temperature low-pressure steam S52 and is supplied to the condenser 54, cooled by the cooling water C51 and condensed, and cooled water C51. Mix in. The condensed water of the steam S52 is mixed and the amount of the cooling water C51 is increased, and the increased amount is returned to the ground from the reduction well X52.

The hot water W53 branched from the hot water W51 pumped from the ground flows through the conduit 63 and is introduced into the evaporator 71 of the second-class absorption heat pump. After heating the water in the evaporator 71, the regenerator It is introduced into 73, and after heating the lithium bromide aqueous solution in the regenerator 73, it is returned to the ground from the reduction well X51.

The water in the evaporator 71 is heated by the hot water W53 pumped from the ground to become steam, and this steam is absorbed by the lithium bromide aqueous solution in the absorber 72 at the same pressure. At this time, in the absorber 72, when the lithium bromide aqueous solution absorbs steam, heat of absorption is generated, and the heat of absorption heats the hot water W54 from the gas-water separator 51. The lithium bromide aqueous solution in the absorber 72 that has absorbed the steam is supplied into the regenerator 73 via the heat exchanger 75, and is boiled in the regenerator 73 by heating from the hot water that has passed through the evaporator 71, and is boiled in the absorber 73. The vapor absorbed in 72 is released. Then, it is returned to the absorber 72 via the heat exchanger 75. The steam generated from the lithium bromide aqueous solution boiling in the regenerator 73 is cooled by the cooling water C52 in the condenser 74 at the same pressure and returned to water, and this water is returned to the evaporator 71. In the condenser 74, the heat of condensation generated when the steam from the regenerator 73 is condensed is carried to the cooling tower 76 by the cooling water C52 and discharged from the cooling tower 76 to the atmosphere.

In power generation mode operation, the valve 77 on the conduit connecting the bottom of the evaporator 71 and the absorber 72 is closed, the valve 78 on the conduit connecting the condenser 74 and the bottom of the regenerator 73 is closed, and the evaporator. Water is accumulated inside the 71 and the condenser 74, and the lithium bromide aqueous solution is accumulated inside the absorber 72 and the regenerator 73.

Further, in the operation of this power generation mode, the flow path switching valves 83 and 87 are opened, and the flow path switching valves 84, 85, 88 and 89 are closed, so that the hot water W54 flows to the heat exchanger 81. Without flowing between the air-water separator 51 and the absorber 72, the cooling water C52 circulates between the condenser 74 and the cooling tower 56 without flowing to the heat exchanger 81.

When the power generation is urgently stopped due to the occurrence of an electric accident, the pumping of the hot water W51 from the ground is stopped, and the power generation mode operation is switched to the power failure mode operation without delay.

In this power failure mode operation, the valve 77 on the conduit connecting the bottom of the evaporator 71 and the absorber 72 and the valve 78 on the conduit connecting the regenerator 73 and the bottom of the condenser 74 open to drain the water in the evaporator 71. The lithium bromide aqueous solution in the absorber 72 is diluted by flowing into the absorber 72, and the water in the condenser 74 is allowed to flow into the regenerator 73 to dilute the lithium bromide aqueous solution in the regenerator 73. When the lithium bromide aqueous solution is diluted to 55% or less, lithium bromide does not crystallize even at room temperature. At this time, since the heat of dilution of lithium bromide is generated in the absorber 72 and the regenerator 73, it is necessary to discharge the heat of dilution to the outside of the system without delay.

In the operation in the power failure mode, the valves 83 and 87 for switching the flow path are closed, and the valves 84, 85, 88 and 89 for switching the flow path are opened. As a result, the hot water W54 circulates between the air-water separator 51, the absorber 72, and the heat exchanger 81, and the cooling water C52 circulates between the condenser 74, the heat exchanger 81, and the cooling tower 76, and heat is generated. In the exchanger 81, heat is exchanged between the hot water W54 and the cooling water C52, and the heat held inside the air-water separator 51 is carried to the heat exchanger 81 by the hot water W54, and the cooling water in the heat exchanger 81. It is transmitted to C52, carried to the cooling tower 76 by the cooling water C52, and discharged from the cooling tower 76 into the atmosphere.

In this power failure mode operation, the flow of the lithium bromide aqueous solution in the Type 2 absorption heat pump continues the same operation as in the power generation mode operation, whereby the heat of dilution of lithium bromide generated in the regenerator 73 is regenerated. It is carried to the absorber 72 by the lithium bromide aqueous solution that circulates in the vessel 73, the heat exchanger 75, and the absorber 72. The heat of dilution of lithium bromide in the absorber 72 and the heat of dilution of lithium bromide in the regenerator 73 carried to the absorber 72 are transferred to the hot water W54 and carried to the heat exchanger 81 by the hot water W54. It is transmitted to the cooling water C52 in the heat exchanger 81, carried to the cooling tower 76 by the cooling water C52, and discharged from the cooling tower 76 into the atmosphere.

According to this embodiment, when the power generation is urgently stopped due to an electric accident, the heat possessed by the device and the heat of dilution of the lithium bromide aqueous solution can be discharged to the outside without delay. The effect of eliminating damage due to pressure rise in a geothermal power generation system with a type heat pump can be obtained.

FIG. 11 shows the pressure change in the air-water separator 11 or 51 of a geothermal power generation system having a second-class absorption heat pump before and after the implementation of the present invention when power generation is urgently stopped due to an electric accident. The model diagram of is shown.

In the steam separator 11 or 51 before carrying out this embodiment, when the power generation is urgently stopped due to an electric accident and the operation is switched to the stop mode operation, the steam turbine 12 or 52 is changed from the chiller 11 or 51. The temperature rises and the pressure rises due to the elimination of the destination of the steam supplied to and the heat of dilution of lithium bromide in the absorber 32 or 72 and the regenerator 33 or 73.

At this time, since the Type 2 absorption heat pump continues to operate, the hot water in the air-water separator 11 or 51 circulates between the air-water separator 11 or 51 and the absorber 32 or 72 while circulating in the absorber 32. Alternatively, the lithium bromide aqueous solution in 72 is heated to lower its own temperature, and the heated lithium bromide aqueous solution in the absorber 32 or 72 circulates between the regenerator 33 or 73 in the regenerator. Self-evaporation at 33 or 73 lowers its own temperature, and the steam generated at 33 or 73 in the regenerator moves to the condenser 34 or 74, is cooled by the cooling water C12 or C52, condenses, and condenses. The water is returned to the regenerator 33 or 73. In the condenser 31 or 71, the amount of heat generated when the steam is condensed is carried to the cooling tower 36 or 76 by the cooling water C12 or C52, and is discharged to the atmosphere from the cooling tower 36 or 76.

When this embodiment is not carried out, the absorber 32 or 72, the regenerator 33 or 73, the condenser 34 or 74, and the cooling tower 36 are released before the heat retained in the air-water separator 11 or 51 is released to the outside of the system. Alternatively, since heat exchange is performed in four stages of 76, the cooling rate becomes slow. Therefore, immediately after the power failure, the pressure in the steam separator 11 or 51 rises significantly, and it takes a lot of time for the pressure to drop.

On the other hand, when this embodiment is carried out, the heat exchange in the heat exchanger 41 or 81 and the cooling tower 36 or 76 takes place before the heat retained in the air-water separator 11 or 51 is discharged to the outside of the system. Therefore, the cooling rate is high, and immediately after a power failure, the pressure rise of the air-water separator 11 or 51 is small, and this pressure drops in a short time.

In short, according to this embodiment, when power generation is urgently stopped due to an electric accident, the heat possessed by the geothermal power generation system having a second-class absorption heat pump and the heat of dilution of the lithium bromide aqueous solution are dissipated to the outside of the system without delay. Therefore, it is possible to obtain the effect of eliminating device damage due to an increase in pressure.

In this embodiment, it is interlocked with a steam separator (11) to which boiler water is supplied, a steam turbine (12) to which steam discharged from the steam separator (11) is supplied, and the steam turbine (12). The generator (13), the water condensing device (14) in which the steam discharged from the steam turbine (12) is condensed, and the boiler water condensed by the water condensing device (14) are supplied to the air-water separator (11). A second-class absorption heat pump having a water supply pump (16), an evaporator (31), an absorber (32), a regenerator (33), a condenser (34), a heat exchanger (35), and a cooling tower (36). , A conduit (24) through which hot water circulating between the air-water separator (11) and the absorber (32) flows, and cooling water circulating between the condenser (34) and the cooling tower (36). Between the conduit (26) through which the hot water flows, the heat exchanger (41) in which the hot water and the cooling water exchange heat, the air-water separator (11), the absorber (32), and the heat exchanger (41). The conduit (27) through which the hot water circulates, the conduit (28) through which the cooling water circulates between the condenser (34), the heat exchanger (41) and the cooling tower (36) is provided. It is characterized by being. Further, when the generator (13) is in power generation operation, the hot water does not flow in the conduit (27), the cooling water does not flow in the conduit (28), and the generator (13) does not flow. ) Is stopped, and during the power generation mode operation, the hot water flows in the conduit (27), and the cooling water flows in the conduit (28). Further, a steam separator (51) to which hot water pumped from the ground is supplied, a steam turbine (52) to which steam discharged from the steam separator (51) is supplied, and a steam turbine (52). An interlocking generator (53), a water condensing device (54) that condenses the steam emitted from the steam turbine (52), an evaporator (71) and an absorber (72), a regenerator (73), and a condenser (74). ), A second-class absorption heat pump having a heat exchanger (75) and a cooling tower (76), and a conduit (64) through which hot water circulating between the air-water separator (51) and the absorber (72) flows. ), A conduit (66) through which cooling water circulating between the condenser (74) and the cooling tower (76) flows, a heat exchanger (81) in which the hot water and the cooling water exchange heat, and the air water. The conduit (67) through which the hot water circulates between the separator (51), the absorber (72), and the heat exchanger (81), the condenser (74), and the heat exchanger (81). It is characterized by including a conduit (68) through which the cooling water circulating between the cooling towers (76) flows. Further, when the generator (53) is in power generation operation, the hot water does not flow in the conduit (67), the cooling water does not flow in the conduit (68), and the generator (53) does not flow. ) Is stopped, the hot water flows in the conduit (67), and the cooling water flows in the conduit (68).

According to this embodiment, when the power generation is stopped, the power generation mode can be switched to the power failure mode without delay, and the heat held in the geothermal power generation system and the heat of dilution of the lithium bromide aqueous solution can be dissipated to the outside of the system. , The effect of eliminating device damage due to increased pressure can be obtained. The geothermal power generation system with a second-class absorption type heat pump has a feature of higher power generation efficiency than the conventional flash type geothermal power generation, and it is possible to generate power with a small amount of hot water pumped from the ground. Therefore, this embodiment has the effect of providing a safe, compact, and economical geothermal power generation system with high output.

The present invention can be widely applied to geothermal power plants and the like.

11 Brackish water separator
13 Steam turbine
15 generator
16 Condenser
17 Cooling tower
19 Pressurizing pump
21 Vessel 31 Evaporator
32 absorber
33 Regenerator
34 condenser
W11 Hot water S11 Steam C11 Cooling water V11 Production well X11 Reduction well
 

Claims (3)

A conduit through which hot water pumped from the ground flows, a pressurizing pump installed at a location in the ground of this conduit, a steam separator to which the hot water is supplied by this pressurizing pump, and a steam separator generated from this steam separator. A steam turbine to which steam is supplied, a generator interlocking with this steam turbine, a condenser in which steam emitted from the steam turbine condenses, an evaporator and an absorber and a regenerator, a condenser, a heat exchanger and a cooling tower. It is characterized by having a second-class absorption type heat pump, a conduit through which hot water circulates between the steam separator and the absorber, and a conduit through which hot water flows from the steam separator to the evaporator. Geothermal power generation system. A steam separator to which hot water pumped from the ground is supplied, a steam separator to which hot water in the steam separator is supplied, a conduit connecting the steam separator and the steam separator, A pressurizing pump installed in the middle of this conduit, a steam turbine to which steam generated from the steam separator, a generator interlocking with the steam turbine, and a water condensing device in which steam emitted from the steam turbine is condensed. A second-class absorption heat pump having an evaporator, an absorber, a regenerator, a condenser, a heat exchanger, and a cooling tower, a conduit through which hot water circulates between the steam separator and the absorber, and the steam. A geothermal power generation system comprising a conduit through which hot water flows from a separator to the evaporator. A steam separator to which hot water pumped from the ground is supplied, a steam separator to which hot water in the steam separator is supplied, a conduit connecting the steam separator and the steam separator, A pressurizing pump installed in the middle of this conduit, a steam turbine to which steam generated from the steam separator is supplied, a generator interlocking with the steam turbine, and a water condensing device in which steam emitted from the steam turbine is condensed. A second-class absorption heat pump having an evaporator, an absorber, a regenerator, a condenser, a heat exchanger, and a cooling tower, a conduit through which hot water circulates between the steam separator and the absorber, and the steam. A geothermal power generation system comprising a conduit through which hot water flows from a separator to the evaporator.

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